Like Jill I also have many sketchbooks full of work and this is the method I have come up with that works for me. I have one or two sketchbooks going at once. Although I don't draw every day I do have designated times twice a week to put pen to paper. After a couple of weeks the pages start to really add up. I then start thinking I want to work on a design using teacups and I know I was drawing them a month ago, how do I track it down?
1. At a certain point in my drawing I start to feel like it's time to get my images into the computer. It ends up being every month or two, but if you draw more then 2 times a week you might want to increase the amount of times you scan your work.
2. My scanner is set to scan my work in black & white, 600 dpi. This is what works best with my sketchbook, but every scanner is different, do a few test runs changing the parameters to see what works for you.
3. After I hit scan a screen pops open for me to approve the image. This is an important step, on this screen I name my image based on what is on the page. (ie: teacups spoons daisy March 2015) If you wait to name your scan till you are done, you will not do it, believe me. Faced with 20 scans that need to be opened up just to see what it is, you will just dump them into a folder and be done with it.
4. Once I am done scanning all of my images it is time to put them away. In the past I have put them all into a folder called Sketchbook March 2015, but as I continue to draw I find I need more distinction. I now have individual sub folders called Food, Flowers, Animals... kept inside a folder called Sketchbook.
I hope this helps you get a hold on your drawings. If you do something different let us know, we would love to learn something new.